Stoplight Switch
WARNING: This page is about a different car, the 1995 BMW 525iT. However, it is still accessible from the selected car via links, so may be relevant.
Stoplight switch is at brake pedal arm. To adjust, loosen lock nut and turn adjusting nut until contact plunger touches pedal arm. Adjust length of plunger until about .20-.24" (5-6 mm) is visible. Tighten lock nut.